1. Field of Invention
The present invention relates to a pump.
2. Related Prior Art
Taiwanese Patent Publication No. 446070 teaches an upright pump including internal and external cylinders. This conventional pump includes a base, an internal cylinder mounted on the base, a piston movably received in the internal cylinder, a rod connected with the piston, an external cylinder mounted on the internal cylinder, a pressure gauge assembly mounted on the external cylinder and a nozzle communicated with the pressure gauge assembly through a pipe. The internal cylinder defines a space. A space is confined between the internal cylinder and the external cylinder. The space is communicated with the space through the aperture. The external cylinder defines an aperture near an upper end. The pressure gauge assembly is located at the upper end of the external cylinder. A space defined in the pressure gauge assembly is communicated with the space through the aperture. In pumping, pressurized air flows from the space to the space from which the pressurized air flows the space defined in the pressure gauge assembly through the aperture. This conventional pump is complicated in structure and therefore entails a high cost for fabrication. In addition, the pressurized air has to travel for a distance substantially twice as much as the length of the internal cylinder 20, thus reducing efficiency for pumping.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.
It is the primary objective of the present invention to provide a structurally simple pump equipped with a pressure gauge that can be monitored easily.
According to the present invention, a pump includes a base, a tubular portion formed on the base and with an upper end and a lower end, a pressure gauge communicated with the tubular portion near the upper end, a cylinder communicated with the tubular portion near the lower end, a piston movably received in the cylinder, a rod connected with the piston and a nozzle communicated with the lower end of the tubular portion.
The tubular portion defines a transverse channel. The cylinder defines an aperture. A first joint defines an axial channel and a transverse channel communicated with the axial channel. The first joint is received in the cylinder. A second joint defines an axial channel and first and second transverse channels communicated with the axial channel thereof. The second joint is inserted in the transverse channel of the tubular portion, the aperture of the cylinder and the transverse channel of the first joint so that the first transverse channel is communicated with the axial channel of the first joint and that the second transverse channel is communicated with the transverse channel of the tubular portion.
An annular seal is mounted on the first joint.
Two annular seals are mounted on the second joint so that the first transverse channel of the second joint is positioned between them.
Two annular seals are mounted on the second joint so that the second transverse channel of the second joint is positioned between them.
The second joint is connected, at an end, with the nozzle.
A pipe includes a first end connected with the second joint and a second end connected with the nozzle. A connector may be connected between the pipe and the second joint.
The cylinder defines two apertures through which the second joint is inserted, and the second joint includes, at an end, a head for abutment against the cylinder.
A cup-shaped portion is formed on the tubular portion near the upper end. The cup-shaped portion defines a channel through which the tubular portion is communication with the pressure gauge.
In a first aspect, the first joint is separate from the base. A cylindrical portion extends from the base and defines a transverse channel for receiving the second joint.
In a second aspect, the first joint is integrally formed on the base.
Other objects, advantages and novel features of the invention will become more apparent from the detailed description when taken in conjunction with the drawings.